What is the National Popular Vote Interstate Compact?

The National Popular Vote Interstate Compact is a mechanism for electing the president by national popular vote without amending the Constitution. The Constitution's framers created the Electoral College in Article II, Section 1, which assigns each state a number of electors equal to its total congressional representation and delegates to each state legislature the authority to direct 'the Manner' in which those electors are appointed. The NPVIC uses that delegation: each member state's legislature enacts a statute directing its own electors to cast their electoral votes for the candidate who receives the largest nationwide popular vote total -- the aggregate of all ballots cast in all 50 states and the District of Columbia -- rather than for the winner of just that state. Because any participating state acts under its own constitutional appointment authority, advocates of the compact argue that no constitutional amendment and no act of Congress are needed to implement it.

The compact's threshold mechanism is what prevents a collection of states representing fewer than 270 electoral votes from unilaterally affecting a presidential outcome. The text of the compact provides that it takes effect only when enacted by states whose combined electoral votes equal or exceed 270 -- a majority of the 538 total electoral votes in the modern Electoral College (the current total of 538 reflects 435 House seats, 100 Senate seats, and 3 electoral votes for the District of Columbia under the 23rd Amendment). Until the threshold is met, each member state's pledge is dormant: the member state's electors are appointed by its existing state law, typically the winner-take-all method that 48 states and D.C. use. The threshold is designed so that once crossed, the compact states collectively hold the decisive margin in the Electoral College -- their simultaneous award of all their electoral votes to the national popular-vote winner will, by arithmetic, produce the same outcome in the Electoral College as in the national popular vote.

The constitutional basis for the NPVIC rests primarily on Article II, Section 1's text that 'each State shall appoint, in such Manner as the Legislature thereof may direct,' a number of electors. The Supreme Court has interpreted this clause broadly. In McPherson v. Blacker, 146 U.S. 1 (1892), the Court unanimously held that state legislatures have plenary power over the method of choosing electors, and that a state may change its method from one election to the next. In Chiafalo v. Washington, 591 U.S. 578 (2020), the Supreme Court unanimously upheld state laws that bind electors to vote for the candidate who won the state's popular vote -- and impose penalties or removal for 'faithless' electors who deviate -- reasoning that the 'Manner' delegation extends to directing how electors cast their electoral votes once appointed. Compact proponents argue that directing electors to vote for the national popular-vote winner is an exercise of exactly this legislative power.

Whether the NPVIC requires Congressional consent under Article I, Section 10, Clause 3 of the Constitution is an unsettled legal question. That clause provides that 'No State shall, without the Consent of Congress...enter into any Agreement or Compact with another State.' The Supreme Court has construed this provision in U.S. Steel Corp. v. Multistate Tax Commission, 434 U.S. 452 (1978) and Cuyler v. Adams, 449 U.S. 433 (1981) to require Congressional consent only for compacts that encroach upon or interfere with the supremacy of the United States or the interests of non-member states. NPVIC proponents argue the compact does not encroach on federal supremacy -- it carries out a federal constitutional scheme -- and does not harm non-member states because non-member states retain their own electoral votes and appointment methods unchanged. Critics argue that a compact altering the effective mechanism for choosing the president is precisely the kind of arrangement that shifts power among states in a way that requires Congress to weigh in. Because no federal court has ruled on the merits of the consent question in a post-threshold context, the legal question remains open.

The practical effect of the NPVIC on 2028 would be significant if the compact were to cross the 270 electoral vote threshold before Election Day 2028. Under the compact, each member state's entire electoral-vote delegation would be awarded to the national popular-vote winner -- even if that candidate lost that member state. A candidate who carries California, New York, Texas, and Florida by large margins could win the national popular vote while losing several smaller member states, and those smaller member states' electoral votes would still go to the national-popular-vote winner under the compact. This design means that campaigns operating under an in-effect NPVIC would rationally maximize total votes nationwide -- including running up margins in non-competitive states -- rather than concentrating resources on a small number of swing states. It would also mean that a candidate who wins the national popular vote cannot lose the presidency via the Electoral College, eliminating the 'split outcome' scenarios that occurred in 2000 and 2016. As of mid-2026, the compact has not yet reached its threshold; the winner of the 2028 election will therefore be determined under the existing Electoral College system unless additional states enact the compact before November 2028.